There are a lot of them. Characters who showed up in earlier episodes, only to quietly disappear and never be referred to again.

A prime example is Richie Cunningham's big brother. He was in maybe two or three episodes, then all of a sudden he was never heard from again. Even in later episodes, Howard and Marion would only talk about their two kids, Richie and Joanie, acting as if the third kid never existed.

Another MIA is Spearchucker, a bunkmate of Hawkeye, Trapper, and Maj. Burns. He appeared in a couple of episodes, then was never seen again. No goodbyes or anything.

Any other MIA's from TV Land?

Eric's sister Laurie in That 70's Show. It is as if she never existed (which I think they ripping on Happy Days and Chuck).

Saved by the Bell had a number of regulars from the 1st season who disappear entirely.

While she wasn't really missing I think Sandra from the Cosby show didn't really get much screen time and she never really seem like she was part of the family IMO.

Chuck rules. He taught Richie all he needed to know about basketball and college. I think he slept with Pinkie and was consequently [BANNED] from the family.

Kelly and Jessie disappearing during the Tori episodes was pretty funny. Nikki and Mikey just went to a different high school after the 8th grade, Red Dog. They didn't move out to Cali with Belding and the kids. Same with Milo and Miss Bliss. I'm sure they're still at JFK. On that note, remember Zack mysteriously had two fathers, the one who hits on Miss Bliss and the one whom he has to call on his phone in that touching moment only eclipsed by "I'm so excited! I'm so excited! I'm so ... scared."

das

How about that little kid on Married with Children.
Name was 7 or something like that.

What about Moira Kelly's character on the West Wing.
She was there the 1st season. Gone the next.

I think one of the Winslow kids on Family Matters just disappeared, a season or 2 into the series. But I can't remember exactly who she was or why she was booted.

I remember seeing episodes of that show before they introduced Urkle.

Pre-Urkle: Very Cosby Show-ish

With Urkle: pretty much show after show of Urkle's hijink's.

I mean, i liked the show but how many years of Urkle did the world really need? Any why did CBS try to keep the show alive?

I used to watched Family Matters like everyweek when I was a kid, even though I barely laughed. I'm curious on what the final episode was about, did Laura and Urkle finally get together or something. And Judy was the kid they wrote off show, I also think they wrote off Aunt Rachel too.

Willy the snitch disappered of Buffy entirly... even though they've shown his bar. I'm not sure why. A few other very minor characters like Percey are gone too, but that's probably because they have no other use more then anything.

Kate is no longer on Angel, even though she was a major major player. It's because she got a new show...

A few reoccuring characters on Sliders disappered after the first season because they moved production from Vancouver to LA.

The final episode was a 2-parter called "Lost In Space". Urkel was chosen to be the first student in space by NASA to test his anti-gravity machine. Meanwhile, Eddie passed the police academy and became a cop. Harriette, concerned for her son's safety, got him demoted to traffic cop, only to find out he was shot on duty. Thanks to a bulletproof vest, he survived, and Harriette understood that as a cop he could be hurt no matter what, so he got back on regular duty. Meanwhile, a satellite hit the space shuttle Urkel was on, and he had to do a spacewalk to get rid of it. He floated into space with it, almost dead, but used the satellite to redirect himself back to the aircraft. He saved the mission and was a hero, but the only thing that made him happy with getting back to his fianceé, Laura, who waited for him with open arms.

Weird

the female terrorist mandy on 24 was in an episode, and then never heard from again.

Brain Stew, was that when the show was on its orginal network (was it ABC or NBC?) or was that the final episode when CBS had it on their friday night lineup?